1880. ] Botanizing on the Colorado Desert. . 791 
and reed-like as seen at a distance, show distinctly, to the nearer 
view, the nodes at which, in other species of the genus, broad, 
flaunting leaves are developed, and at each of these leaf-nodes 
the careful observer detects a pair of minute, awl-shaped appen- 
dages which are technically the leaves of this anomalous Ascle- 
piad of the desert. 
On passing forth from the mountain gorge to the open plain, 
the eye is greeted by an assemblage of such strange-looking veg- 
etable forms as command the wondering attention of all travelers, 
whether scientists or not. Among these the cacti are the most 
conspicuous; some of them globose or cylindrical, resembling so — 
many enormous melons set up on end, having prickly sides and 
bearing flowers and fruits at the top. Others are more like 
orchard trees, with smoothish trunks and well-rounded heads of 
branches bending under a load of pear-shaped fruits. 
One of these cacti (Opuntia bigelowii Engelm.) is, in its gen- 
eral aspect, doubtless a more forbidding thing than any “thorn” 
or “thistle” which the ancestral fugitives from Eden ever met 
with in oriental wilds. If the reader wishes to form a definite 
and tolerably correct idea of this plant’s appearance, let him 
imagine a post four or five feet high and as many inches thick, 
putting forth, from its upper extremity, a half dozen clumsy arms 
or branches of the size and shape of ordinary ball-clubs, the 
trunk and club-shaped branches all so thickly beset with long, 
needle-like, glistening spines, that the spines are actually the only 
part of the plant visible. With such a horrid growth as this the 
grand knolls and lower slopes of all the hills are covered, 
Extremely odd looking and not more odd than beautiful is the 25 
small tree locally known by its Mexican name ocotilla (Fouguiera 
splendens Engelm.). It grows to the height of from eight to 
twelve feet, and in outline is quite precisely fan-shaped. To show 
how this may be, let me describe more particularly its mode w > 
growth. The proper trunk, usually ten or twelve inches in diam- — 
eter, is not more than a foot and a-half high. At just a few 
inches above the surface of the sands this trunk abruptly sepa- 
rates into a dozen or more distinct and almost branchless stems. 
These simple stems rising to the height of eight or ten feet, 
gradually diverge from one another, giving to the whole shrub — 
the outline of a spread fan. Each separate stem 1s clothed — 
throughout with short gray thorns and small dark-green leaves, 
